Solar panels, heat pumps and insulation in Highgate conservation area
In the Highgate conservation area (Haringey), external wall insulation needs planning permission, and so does an air source heat pump on a wall or roof facing the road; one at the back or side, internal and loft insulation and solar panels on a roof slope normally do not. The area has 103 listed buildings; on a listed building solar panels and heat pumps are not permitted development at all and need planning permission and listed building consent. 4,475 homes inside the boundary have an energy certificate: 64.9% are solid-wall homes with no wall insulation, 76.7% heat with a gas boiler and 57.4% are rated D–G; 39 have a heat pump. EPC register November 2026; rules as at 21 October 2026.
Data: EPC register November 2026 (latest certificate per home), conservation area boundaries 3 November 2026, permitted development rules as at 21 October 2026 · calculated 5 November 2026 · Methodology and sources
4,475homes with an energy certificate
64.9%solid walls, no insulation
76.7%heated by a gas boiler
39heat pumps
Article 4: Haringey publishes its Article 4 areas on planning.data.gov.uk and none overlaps this area; a direction can still exist on paper, so check with the council.
What needs planning permission in Highgate
Work (house, not listed)
In a conservation area
Rule
Air source heat pump on a wall or roof facing the road, or nearer the road than the house
Planning permission needed
Part 14 Class G, G.1(j)
Air source heat pump at the back or side (outdoor unit up to 1.5 m³, MCS Planning Standards, one per house — two on a detached house)
No permission needed (permitted development)
Part 14 Class G
Solar panels on a pitched roof (up to 0.2 m proud, not above the ridge)
No permission needed (permitted development)
Part 14 Class A, A.2(c)
Solar panels on a wall, balcony or roof enclosure facing the road
Planning permission needed
Part 14 Class A, A.2(e)
Solar panels on a flat roof (up to 0.6 m above the roof)
Replacement windows and doors of similar appearance
No permission needed (permitted development)
Part 1 Class A, A.3(a)
Listed buildings: 103 in the area (grade I: 4, II*: 4). The table is for houses that are not listed: on a listed building, solar panels and air source heat pumps are not permitted development at all (they need planning permission), and any of these works needs listed building consent.
Flats: 71% of the certified homes here are flats or maisonettes. Homes in a block of flats have no householder rights for alterations; heat pumps and solar have their own, tighter rules for blocks of flats.
The homes in the area (latest certificate per home, n = 4,475)
Walls
Homes
Share
Solid wall (brick or stone), no insulation
2,904
64.9%
Cavity wall, unfilled
401
9.0%
Modern wall (U-value from the design)
255
5.7%
Cavity wall, insulated (as built or unspecified)
249
5.6%
Other or not known
149
3.3%
Cavity wall, filled
133
3.0%
Timber frame
123
2.7%
Cavity wall, partly insulated
91
2.0%
Solid wall, internal insulation
81
1.8%
Solid wall, insulated
42
0.9%
Solid wall, partly insulated
20
0.4%
Cavity wall, internal or external insulation
17
0.4%
Solid wall, external insulation
10
0.2%
Heating
Homes
Share
Gas boiler
3,433
76.7%
Communal heating
680
15.2%
Electric (storage heaters, panels, boiler)
313
7.0%
Heat pump
39
0.9%
LPG
8
0.2%
Oil
1
0.0%
Solid fuel (wood, coal)
1
0.0%
Loft / roof insulation
Homes
Share
No insulation
819
18.3%
Under 200 mm
426
9.5%
200 mm or more
231
5.2%
Insulated (depth not recorded)
658
14.7%
Flat or other home above
2,171
48.5%
Other
169
3.8%
Windows
Homes
Share
Double glazed
3,206
71.6%
Single glazed
987
22.1%
Secondary glazing
252
5.6%
Triple glazed
30
0.7%
CDE
Energy rating: B 238 (5.3%) · C 1,667 (37.3%) · D 1,882 (42.1%) · E 585 (13.1%) · F 90 (2.0%) · G 13 (0.3%). Houses and bungalows: 29% of the homes; solar panels on 0.3% of the certificates. Most common build period on the certificates: 1900-1929. Designated: 21 December 1967.
Compared with Haringey and England
Share of homes
Highgate
All 38 areas in Haringey
England
Solid walls, no insulation
64.9%
66.4%
48.7%
Gas boiler
76.7%
80.1%
66.4%
Rated D–G
57.4%
—
56.5%
Caveats
Certificates describe a home when it was assessed; 51% of these are from 2020 or later (latest 28 October 2026). “No insulation (assumed)” is the assessor's default for older walls.
The rules are England's national permitted development rules (General Permitted Development Order 2015, Schedule 2, as at 21 October 2026). They do not cover building regulations or a council's own conditions. This is not a planning decision: ask Haringey if in doubt.
Boundary: London Borough of Haringey via planning.data.gov.uk (entity 44014358, reference CA1, 227.7 ha); the council's appraisal or map. Homes are placed by the coordinates of their UPRN (OS Open UPRN); addresses are not shown.